Excessive number of browse definition request on simple item page.

[KoenP]

Describe the bug

Each ItemPageFieldComponent performs a separate request to obtain potential browse indexes for the relevant metadata its relevant metadata fields.

To Reproduce

Go to a simple item page for an item with enough metadata to spawn multiple ItemPageFieldComponents.
In the browser's network log, observe the repeated GET requests to the http://localhost:8080/server/api/discover/browses/search/byFields?fields=... endpoint.
This slows down the page.

Expected behavior

Since all this information has already been requested for the "All of DSpace" navbar menu, we should be able to retrieve this information from the cache, rather than re-requesting it.

Related work

#3701

[alanorth]

Thanks @KoenP! I confirm I see lots of requests for /server/api/discover/browses/search/byFields?fields= on the simple item page of our DSpace 7.6 repository.

Tagging this issue as affecting all current branches.